It leads to a build-up of defective beta amyloid protein - a hallmark of Alzheimer's disease. The mice eating a low-AGEs diet were able to prevent the production of damaged amyloid.

This subject has so far not been well studied in people, and we don't yet know whether the amount of AGEs in our diet might affect our risk of dementiaDr Simon Ridley, Alzheimer's Research UK

The mice performed less well in physical and thinking tasks after their AGEs-rich diet.

A short-term analysis of people over 60 suggested a link between high levels of AGEs in the blood and cognitive decline.

'Effective treatment'

The study concluded: "We report that age-related dementia may be causally linked to high levels of food advanced glycation end products.

"Importantly, reduction of food-derived AGEs is feasible and may provide an effective treatment strategy."

Derek Hill, a professor of medical imaging sciences at University College London, commented: "The results are compelling.

"Because cures for Alzheimer's disease remain a distant hope, efforts to prevent it are extremely important, but this study should be seen as encouraging further work, rather than as providing definitive answers.

"But it is grounds for optimism - this paper adds to the body of evidence suggesting that using preventative strategies might reduce the prevalence of Alzheimer's disease and other dementias in society and that could have very positive impact on us all."

Dr Simon Ridley, from the charity Alzheimer's Research UK, said: "Diabetes has previously been linked to an increased risk of dementia, and this small study provides some new insight into some of the possible molecular processes that may link the two conditions.

"It's important to note that the people in this study did not have dementia. This subject has so far not been well studied in people, and we don't yet know whether the amount of AGEs in our diet might affect our risk of dementia."